<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>08-实参可以是变量</title>
  </head>

  <body>
    <script>
      //求 n ~ m 的累加和
      function getSum(n = 0, m = 0) {
        let sum = 0
        for (let i = n; i <= m; i++) {
          sum += i
        }
        console.log(sum)
      }
      // getSum()
      // getSum(1, 2)
      let num1 = +prompt('请输入第一个数：')
      let num2 = +prompt('请输入第二个数：')
      //调用函数
      getSum(num1, num2) //实参可以是变量
    </script>
  </body>
</html>
